The present invention relates generally to the field of fluid containers for use in industrial liquid delivery systems. In particular, the present invention relates to a fluid container that helps minimize the formation of gas microbubbles in liquid chemical streams.
In many industrial process applications, fluid containers are employed as a source of process liquids for liquid delivery systems. Oftentimes the fluid containers are fabricated and filled at locations remote from the end-use facility. In such situations, the end-use facility then either directly incorporates the fluid containers into a liquid delivery system or empties the liquid from the fluid containers into a reservoir connected to the liquid delivery system.
In certain industrial process applications, the presence of gas microbubbles in liquid traveling through a liquid delivery system may have harmful effects. For example, when liquids are deposited on a substrate to form a layer, the presence of microbubbles in the deposited liquids may cause defects in the deposited layer or subsequent deposited layers. Depending upon the pressure conditions in the fluid container and the liquid delivery system, the presence of headspace gas in the fluid container and/or the liquid delivery system may contribute to the formation of microbubbles in the liquid stream.
In the semiconductor industry, for example, a common manufacturing step in producing integrated circuits involves depositing photoresist solution on silicon wafers. The presence of microbubbles in the photoresist solution will typically yield defect sites on the surface of the wafer in subsequent process steps. As features on integrated circuits have continued to become smaller, the presence of microbubbles has posed an increasing danger to the quality of integrated circuits. Moreover, when microbubbles are observed in industrial liquid delivery systems, the systems are often purged until the microbubbles are eliminated, which can result in the wasting of expensive chemical liquids. Thus, it is advantageous to eliminate, or at least minimize, the presence of microbubbles in liquid delivery systems.
Given these problems associated with the formation of microbubbles, there is a need for a fluid container that removes headspace gas and helps reduce microbubble formation in liquid traveling through liquid delivery systems.